Signaling system



Nov. 1, 1927. 1,647,284

J. C. FIELD SIGNALING SYSTEM Filed Oct- 3, 1919 IIIIHI' //71 e/7f0/-Jase of; c F//d y j v Patented Nov. 1, 1927.

UNITED STATES- PATENT OFFICE.

JOSEPH C. FIELD, OF ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRICCOM", PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SIGNALING SYSTEM.

Application filed October 3, 1919. Serial No. 328,275.

This invention relates to signaling systems and particularly toimprovements in telegraph signaling systems. I

The principal object of this invention is to provide a, simplified andan improved answer-back signaling means whereby an operator, uponsignaling a distant station, may be automatically apprised of thereceipt of the proper signal at the desired station.

A further object is to provide a system which is efiicient and reliablein operation and one which requires a minimum number of operating parts.

For the accomplishment of the above objects, the invention contemplatesthe embodiment of a plurality of sending and receiving stations, withmeans at the sending stations to transmit code signals, and means at thereceiving stations selectively responsive to the code signals, andadditional means thereat to-automatically signal back to the sending ororiginating station after receipt of the code signal. The selectiveresponsive means at the receiving stations may comprise suitable codeselectors responsive to predetermined groups of code impulses, and theanswer-back equipment may comprise suitably timed electro-responsivedevices for periodically opening and closing the line circuit. Eachstation may, if desired, be equipped with complete transmitting andreceiving apparatus.

The above and other objects of this invention will be fully set forth inthe following description and claims and will be more readily understoodby reference to the accompanying drawing wherein the preferredembodiment of the invention is shown.

Referring to the drawing, A, B, C and D represent sending and receivingstations interconnected by a main line L. At stations :A and D there isshown a telegraph key 10 for sending impulses over the line L, while atstations B and 0 there is shown in addition to the usual transmittingkeys 10, re-

- ceiving apparatus under the control of the line relays 14. The linerelays 11 at stations A and D are each provided with an armature 13 forcontrolling a local circuit 12 i nwhich may be included an ordinarytelegraph receiving sounder 50.

It will be understood that the'line circuit is normally closed througheach key or through an auxiliary switch associated therewith as is wellunderstood in telegraph practice.

Referring particularly to the apparatus and circuits shown at stations Band C, each line relay 14 is provided with an armature 16 forcontrolling the apparatus connected in a local circuit 17, includinglocal battery 15. Connected in the local circuit 17 is, a telegraphsounder 18 which may be used for ordinary signaling purposes. In circuitwith the sounder 18 is a selector switch magnot 19 for operating theselector switch arm 20. This selector is of the type shown in U. S.patent to Gill, No. 906,523, dated December 15, 1908, and is soconstructed that the selector magnet 19 will not be operated operatedwhen predetermined code impulses are transmitted to operate the selectorswitch magnet 19. Under control of the line relay 14 and selector switchmagnet 19 are a plurality of chain connected relays 22, 24 and 26 forcontrolling the operation of a signaling device at the receivingstation, and for sending an answer-back or series of impulses back tothe sending or originating station to operate a suitable indicatingdevice pro vided at such originating or sending station.

Assuming, for example, that the operator at station A desires to call orsignal the operator at station B, the key at station A is operated tosend to line L a series of code impulses which will advance the selectorarm 20 at station B to engage contact 21 and close a local circuitthrough the winding of relay 22. While the selectors 19 at each of thestations connected to the line circuit will respond to the impulses sentout from station B will advance su'fiiciently to engage the contact 21.The closing of the selector contact atstation B completesan energizingcircuit through relay 22, which may be traced from local battery 15,conductor 27 selector switch arm 20, contact 21, winding of relay 22,armature 16 of relay 14 and contact thereof, to the other side of localbattery 15. Relay 22 upon being energized attracts its armatures 28 and29, thereby establishing a holding circuit through relay 22 from battery15, armature 28 and contact of relay 22, winding of relay 22, armatureand contact of relay 14 to the other side of battery 15 and by theattraction of armature 29 establishes an en-' ergizing circuit throughrelay 24 from local battery 15, armature 32 and back contactof relay 26,winding of relay 24, armature 29 and contact of relay 22, to theopposite side of battery 15. Relay 24 thereupon pulls up its armatures30 and 31. The attraction of armature 30 establishes an operatingcircuit through a signaling device 34 from battery 15, armature 30 andfront contact of relay 24, signaling device 34 to the other side ofbattery 15. The attraction of armature 31 establishes an energizingcircuit through relay 26 from battery 15, winding of relay 26,

-' armature 31 and back contact, of relay 24 to the other side ofbattery 15. Relay 26 thereupon pulls up its armatures 32 and 33. Theattraction of armature 33 opens the line circuit L, which is normallyclosed through the armature and back contact of relay 26, and theattraction of armature 32 opens the energizing circuit of relay 24,thereby permitting its armatures 30 and 31 to fall back and open thecircuit through the signaling device 34 and also the energizing circuitthrough relay 26. The instant relay 24 is deenergized and the circuit ofrelay 26 is opened, the armatures 32 and 33 of relay 26 fall back,thereby completing an energizing circuit again as previously tracedthrough relay 24, and closing theline circuit L through armature 33 andback contact of relay 26. The energization of relay 24 again causes theoperation of signaling device 34 and again closes the energizing circuitthrough relay 26. Thus it will be seen that relays 24 and 26 operatealternately and are intercontrolling in such a manner as to open andclose the line circuit periodically at the back contact of relay 33. Theopening and closing of the line circuit at-the back contact of relay 33causes the energization and deenergization of line relay 11 at station Ato thereby operate a local sounder or signaling device, which may beconnected in a well-known manner in the local circuit 12, therebyinforming the operator at the originating or sending station A that thecode 4 signal transmitted to station B has been received.

The operation of relays 24 and 26 may be adjusted, if so desired (byadjusting the travel of their armatures and the tension of their springswhich normally hold the armatures 1n retracted positions), to open andclose the line circuit L a definite or predetermined number of times persecond, thereby causing the signaling device at the sending station tooperate a predetermined number of times per second or to give a codesignal. Also the corresponding relays 24 and 26 at the other stationsconnected to the line may be adjusted to open-and close the line circuita difierent number of times per second, in order to apprise the operatorat the originating or sending station that a particular station'has beensignalled. For example, station B may send back two impulses per second,station C, four impulses per second, and

so on.

The relay 22 at station B is made slowreleasing so that it will notrespond to the opening and closing of the local circuit 17 at thecontacts of relay 14 when the answerback apparatus is functioning tosend impulses back to the originating station. After the operator atstation A has received the answer-back signal, the key at station A maybe opened for a second or more to thereby open the line circuit andcause the armature 16 of line relay 14 to fall back a sufiicient periodof time to cause the deenergization of relay 22, and permit theequipment atthe receiving station including the selector 19, signal 34and answer-back relays 24 and 26 to be restored to normal. The apparatusat station B may also be restored to normal by 0 ening the key or switch10 at that station. Thus it is possible to restore the selector signaland answer-back equipment 'at either the originating or called station.

The signaling device 34 is represented in the accompanylng drawing as alamp. It will be understood, however, that a hell or any other suitablesignaling device may be employed as desired.

The local circuits and equipment shown at station 0 are the same asthose shown and described at station B, except that the circuit forrelay 22 is through a normally closed key 35 instead of through thecontact and armature 16 of main line relay '14. In the arrangement shownat station C, relay 22 need not be slow-releasing. The answerbackequipment at station C when once set in operation will continue tooperate until stopped by the operator opening key 35 at that station.

Although the accompanying drawing shows the preferred embodiment ofapplicants invention, it will be understood that various changes andmodifications ma be made without departing from the spirit of theinvention.

What is claimed is:

1. A signaling system comprising 9. normally closed line circuit,including a central station and a plurality of substations, a variableimpulse transmitter at the central station, a line relay at eachsubstation operated thereby, a step-by-step device. at each of thesubstations selectively responsive to the variable impulses transmittedby said impulse transmitter; it slow to release relay at each of saidsubstations, a circuit for said relay closed by said device in apredetermined position thereof, a locking circuit for said slow relayincluding a contact of said line relay, a pair of relays at eachsubstation, one of said pair having a contact in said line circuit andeach relay controlling the circuit of the other, a circuit for one ofsaid relays closed by said slow relay upon its energization to initiatethe alternate energizat-ion and deenergization of said relays tointerrupt the line circuit, an electro-responsive device in the linecircuit at the central station responsive to said interruptions, andmeans at the central station for interrupting the line circuit for aperiod sufiicient to allow the slow release relay to deenergize andthereby interrupt the operation of said relays.

2. A signaling system comprising a normally closed line circuit,includinga central station and a plurality of substations, a variableimpulse transmitter at the central station, a line relay at eachsubstation operated thereby, a step-by-step device at each of thesubstations selectively responsive to the variable impulses transmittedby said impulse transmitter, a slow to release relay at each of saidsubstations, a circuit for said relay closed by said device in apredetermined position thereof, a locking circuit for said slow relayincluding a contact ofsaid line relay, a pair of relays at eachsubstation, one of said pair having a contact in said line circuit andeach relay controlling the circuit of the other, a circuit for one ofsaid relays closed by said slow relay upon its energization to initiatethe alternate energization and deenergization of said relays tointerrupt the line circuit, an electro-res'ponsive device in the linecircuit at the central station responsive to said interruptions, therelays at the difierent substations being adjusted to interrupt the linecircuit in a manner individual to such stations.

In witness whereof, I hereunto subscribe my name this 30th day ofSeptember, A. D.,

JOSEPH C. FIELD.

